BackgroundColorectal cancer (CRC) is the second most deadly cancer worldwide, with chemo-resistance remaining a major obstacle in CRC treatment. Notably, the imbalance of redox homeostasis-mediated ferroptosis and the modulation of hypoxic tumor microenvironment are regarded as new entry points for overcoming the chemo-resistance of CRC.MethodsInspired by this, we rationally designed a light-activatable oxygen self-supplying chemo-photothermal nanoplatform by co-assembling cisplatin (CDDP) and linoleic acid (LA)-tailored IR820 via enhanced ferroptosis against colorectal cancer chemo-resistance. In this nanoplatform, CDDP can produce hydrogen peroxide in CRC cells through a series of enzymatic reactions and subsequently release oxygen under laser-triggered photothermal to alleviate hypoxia. Additionally, the introduced LA can add exogenous unsaturated fatty acids into CRC cells, triggering ferroptosis via oxidative stress-related peroxidized lipid accumulation. Meanwhile, photothermal can efficiently boost the rate of enzymatic response and local blood flow, hence increasing the oxygen supply and oxidizing LA for enhanced ferroptosis.ResultsThis nanoplatform exhibited excellent anti-tumor efficacy in chemo-resistant cell lines and showed potent inhibitory capability in nude mice xenograft models.ConclusionsTaken together, this nanoplatform provides a promising paradigm via enhanced ferroptosis and alleviated hypoxia tumor microenvironment against CRC chemo-resistance.Graphical

BackgroundNano-sized drug delivery system has been widely studied as a potential technique to promote tumor-specific delivery of anticancer drugs due to its passive targeting property, but resulting in very restricted improvements in its systemic administration so far. There is a requirement for a different approach that dramatically increases the targeting efficiency of therapeutic agents at targeted tumor tissues.MethodsTo improve the tumor-specific accumulation of anticancer drugs and minimize their undesirable toxicity to normal tissues, a tumor-implantable micro-syringe chip (MSC) with a drug reservoir is fabricated. As a clinically established delivery system, six liposome nanoparticles (LNPs) with different compositions and surface chemistry are prepared and their physicochemical properties and cellular uptake are examined in vitro. Subsequently, MSC-guided intratumoral administration is studied to identify the most appropriate for the higher tumor targeting efficacy with a uniform intratumoral distribution. For efficient cancer treatment, pro-apoptotic anticancer prodrugs (SMAC-P-FRRG-DOX) are encapsulated to the optimal LNPs (SMAC-P-FRRG-DOX encapsulating LNPs; ApoLNPs), then the ApoLNPs are loaded into the 1 μL-volume drug reservoir of MSC to be delivered intratumorally for 9 h. The tumor accumulation and therapeutic effect of ApoLNPs administered via MSC guidance are evaluated and compared to those of intravenous and intratumoral administration of ApoLNP in 4T1 tumor-bearing mice.ResultsMSC is precisely fabricated to have a 0.5 × 4.5 mm needle and 1 μL-volume drug reservoir to achieve the uniform intratumoral distribution of LNPs in targeted tumor tissues. Six liposome nanoparticles with different compositions of 1-palmitoyl-2-oleoyl-glycero-3-phosphocholine (PC), 1,2-dioleoyl-sn-glycero-3-phospho-L-serine (PS), 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP), and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy (polyethylene glycol)2000] (PEG2000-DSPE) are prepared with average sizes of 100–120 nm and loaded into the 1 μL-volume drug reservoir in MSC. Importantly negatively charged 10 mol% of PS-containing LNPs are very slowly infused into the tumor tissue through the micro-syringe of the MSC over 6 h. The intratumoral targeting efficiency of MSC guidance is 93.5%, effectively assisting the homogeneous diffusion of LNPs throughout the tumor tissue at 3.8- and 2.7-fold higher concentrations compared to the intravenous and intratumoral administrations of LNPs, respectively. Among the six LNP candidates 10 mol% of PS-containing LNPs are finally selected for preparing pro-apoptotic SMAC-P-FRRG-DOX anticancer prodrug-encapsulated LNPs (ApoLNPs) due to their moderate endocytosis rate high tumor accumulation and homogenous intratumoral distribution. The ApoLNPs show a high therapeutic effect specifically to cathepsin B-overexpressing cancer cells with 6.6 μM of IC50 value while its IC50 against normal cells is 230.7 μM. The MSC-guided administration of ApoLNPs efficiently inhibits tumor growth wherein the size of the tumor is 4.7- and 2.2-fold smaller than those treated with saline and intratumoral ApoLNP without MSC, respectively. Moreover, the ApoLNPs remarkably reduce the inhibitor of apoptosis proteins (IAPs) level in tumor tissues confirming their efficacy even in cancers with high drug resistance.ConclusionThe MSC-guided administration of LNPs greatly enhances the therapeutic efficiency of anticancer drugs via the slow diffusion mechanism through micro-syringe to tumor tissues for 6 h, whereas they bypass most hurdles of systemic delivery including hepatic metabolism, rapid renal clearance, and interaction with blood components or other normal tissues, resulting in the minimum toxicity to normal tissues. The negatively charged ApoLNPs with cancer cell-specific pro-apoptotic prodrug (SMAC-P-FRRG-DOX) show the highest tumor-targeting efficacy when they are treated with the MSC guidance, compared to their intravenous or intratumoral administration in 4T1 tumor-bearing mice. The MSC-guided administration of anticancer drug-encapsulated LNPs is expected to be a potent platform system that facilitates overcoming the limitations of systemic drug administration with low delivery efficiency and serious side effects.Graphical

BackgroundNoninvasive monitoring of tear glucose levels can be convenient for patients to manage their diabetes mellitus. However, there are issues with monitoring tear glucose levels, such as the invasiveness of some methods, the miniaturization, inaccuracy, or the high cost of wearable devices. To overcome the issues, we newly designed a sucking disk-type (SD) strip biosensor that can quickly suck tear fluid and contains cerium oxide nanoparticle (CNP) that causes a unique color change according to the glucose level of the tear without complicated electronic components.MethodsThe SD strip biosensor composed of three distinct parts (tip, channel, and reaction chamber) was designed to contain the sensing paper, onto which tear fluid can be collected and delivered. The sensing paper treated with CNP/APTS (aminopropyltriethoxysilane) /GOx (glucose oxidase) was characterized. Then we carried out the reliability of the SD strip biosensor in the diabetic rabbit animals. We quantitatively analyzed the color values of the SD strip biosensor through the colorimetric analysis algorithm.ResultsWe contacted the inferior palpebral conjunctiva (IPC) of a diabetic rabbit eye using an SD strip biosensor to collect tears without eye irritation and successfully verified the performance and quantitative efficacy of the sensor. An image processing algorithm that can optimize measurement accuracy is developed for accurate color change measurement of SD strip biosensors. The validation tests show a good correlation between glucose concentrations measured in the tear and blood.ConclusionOur findings demonstrate that the CNP-embedded SD strip biosensor and the associated image processing can simply monitor tear glucose to manage diabetes mellitus.Graphical

BackgroundBrain-derived exosomes released into the blood are considered a liquid biopsy to investigate the pathophysiological state, reflecting the aberrant heterogeneous pathways of pathological progression of the brain in neurological diseases. Brain-derived blood exosomes provide promising prospects for the diagnosis of neurological diseases, with exciting possibilities for the early and sensitive diagnosis of such diseases. However, the capability of traditional exosome isolation assays to specifically isolate blood exosomes and to characterize the brain-derived blood exosomal proteins by high-throughput proteomics for clinical specimens from patients with neurological diseases cannot be assured. We report a magnetic transferrin nanoparticles (MTNs) assay, which combined transferrin and magnetic nanoparticles to isolate brain-derived blood exosomes from clinical samples.MethodsThe principle of the MTNs assay is a ligand-receptor interaction through transferrin on MTNs and transferrin receptor on exosomes, and electrostatic interaction via positively charged MTNs and negatively charged exosomes to isolate brain-derived blood exosomes. In addition, the MTNs assay is simple and rapid (< 35 min) and does not require any large instrument. We confirmed that the MTNs assay accurately and efficiently isolated exosomes from serum samples of humans with neurodegenerative diseases, such as dementia, Parkinson's disease (PD), and multiple sclerosis (MS). Moreover, we isolated exosomes from serum samples of 30 patients with three distinct neurodegenerative diseases and performed unbiased proteomic analysis to explore the pilot value of brain-derived blood protein profiles as biomarkers.ResultsUsing comparative statistical analysis, we found 21 candidate protein biomarkers that were significantly different among three groups of neurodegenerative diseases.ConclusionThe MTNs assay is a convenient approach for the specific and affordable isolation of extracellular vesicles from body fluids for minimally-invasive diagnosis of neurological diseases.

BackgroundAging skin is characterized by a disturbed structure and lack of blood supply, which makes it difficult to heal once injured. ADSCs secrete large amounts of cytokines, which promote wound healing and vascular regeneration through paracrine secretion, and the number of cytokines can be elevated by hypoxic pretreating. However, the components of ADSCs are difficult to retain in wounds. Gelatin methacrylate (GelMA) is a photopolymerizable hydrogel synthesized from gelatin and has recently emerged as a potentially attractive material for tissue engineering applications. GelMA loaded with concentrated hypoxic pretreated ADSCs conditioned medium could provide a new method of treating wounds in aged skin.MethodsPrimary ADSCs were isolated from human adipose tissue and characterized by flow cytometry and differentiation test. ADSCs in passages 4-6 were pretreated in the hypoxic and normoxic environments to collect conditioned medium, the conditioned medium was then concentrated to prepare concentrated ADSCs conditioned medium(cADSC-CM)(the one collected from ADSCs under hypoxia was called hypo-CM ,and the one from normoxia was called nor-CM). The concentration of cytokines was detected. After treated with cADSC-CM, the abilities of proliferation, migration, and tube formation of human umbilical vascular endothelial cells (HUVECs) were assayed, and Akt/mTOR and MAPK signal pathway was detected using western blotting. GelMA+hypo-CM hydrogel was prepared, and a comprehensive evaluation of morphology, protein release efficiency, degradation rate, mechanical properties, and rheology properties were performed. Full-thickness skin wounds were created on the backs of 20-month-old mice. After surgery, GelMA, GelMA+F12, GelMA+hypo-CM, and GelMA+nor-CM were applied to the wound surface respectively. H&E, Masson, and immunohistochemistry staining were performed, and a laser Doppler perfusion imager was used to evaluate the blood perfusion. The student’s t-test was used for analysis between two groups and a one-way analysis of variance (ANOVA) was used for analysis among multi groups.ResultsOur results revealed that 1) wounds in aged skin healed more slowly than that in young skin and exhibited poorer perfusion; 2) hypoxic pretreated ADSCs secreted more cytokines including VEGF by activating HIF1α; 3) hypo-CM promoted proliferation and migration of HUVECs through VEGF/Akt/mTOR and MAPK signal pathway; 4) GelMA-hypoCM accelerated wound healing and angiogenesis in aged skin in vivo.ConclusionGelMA loaded with concentrated hypoxic pretreated adipose-derived mesenchymal stem cells conditioned medium could accelerate wound healing in aged skin by promoting angiogenesis.

Personalized medicine aims to provide tailored medical treatment that considers the clinical, genetic, and environmental characteristics of patients. iPSCs have attracted considerable attention in the field of personalized medicine; however, the inherent limitations of iPSCs prevent their widespread use in clinical applications. That is, it would be important to develop notable engineering strategies to overcome the current limitations of iPSCs. Such engineering approaches could lead to significant advances in iPSC-based personalized therapy by offering innovative solutions to existing challenges, from iPSC preparation to clinical applications. In this review, we summarize how engineering strategies have been used to advance iPSC-based personalized medicine by categorizing the development process into three distinctive steps: 1) the production of therapeutic iPSCs; 2) engineering of therapeutic iPSCs; and 3) clinical applications of engineered iPSCs. Specifically, we focus on engineering strategies and their implications for each step in the development of iPSC-based personalized medicine.

BackgroundTo support bone regeneration, 3D-printed templates function as temporary guides. The preferred materials are synthetic polymers, due to their ease of processing and biological inertness. Poly(lactide-co-trimethylene carbonate) (PLATMC) has good biological compatibility and currently used in soft tissue regeneration. The aim of this study was to evaluate the osteoconductivity of 3D-printed PLATMC templates for bone tissue engineering, in comparison with the widely used 3D-printed polycaprolactone (PCL) templates.MethodsThe printability and physical properties of 3D-printed templates were assessed, including wettability, tensile properties and the degradation profile. Human bone marrow-derived mesenchymal stem cells (hBMSCs) were used to evaluate osteoconductivity and extracellular matrix secretion in vitro. In addition, 3D-printed templates were implanted in subcutaneous and calvarial bone defect models in rabbits.ResultsCompared to PCL, PLATMC exhibited greater wettability, strength, degradation, and promoted osteogenic differentiation of hBMSCs, with superior osteoconductivity. However, the higher ALP activity disclosed by PCL group at 7 and 21 days did not dictate better osteoconductivity. This was confirmed in vivo in the calvarial defect model, where PCL disclosed distant osteogenesis, while PLATMC disclosed greater areas of new bone and obvious contact osteogenesis on surface.ConclusionsThis study shows for the first time the contact osteogenesis formed on a degradable synthetic co-polymer. 3D-printed PLATMC templates disclosed unique contact osteogenesis and significant higher amount of new bone regeneration, thus could be used to advantage in bone tissue engineering.

BackgroundCells in the human body experience different growth environments and conditions, such as compressive pressure and oxygen concentrations, depending on the type and location of the tissue. Thus, a culture device that emulates the environment inside the body is required to study cells outside the body.MethodsA blanket-type cell culture device (Direct Contact Pressing: DCP) was fabricated with an alginate-based hydrogel. Changes in cell morphology due to DCP pressure were observed using a phase contrast microscope. The changes in the oxygen permeability and pressure according to the hydrogel concentration of DCP were analyzed. To compare the effects of DCP with normal or artificial hypoxic cultures, cells were divided based on the culture technique: normal culture, DCP culture device, and artificial hypoxic environment. Changes in phenotype, genes, and glycosaminoglycan amounts according to each environment were evaluated. Based on this, the mechanism of each culture environment on the intrinsic properties of conserving chondrocytes was suggested.ResultsChondrocytes live under pressure from the surrounding collagen tissue and experience a hypoxic environment because collagen inhibits oxygen permeability. By culturing the chondrocytes in a DCP environment, the capability of DCP to produce a low-oxygen and physical pressure environment was verified. When human primary chondrocytes, which require pressure and a low-oxygen environment during culture to maintain their innate properties, were cultured using the hydrogel blanket, the original shapes and properties of the chondrocytes were maintained. The intrinsic properties could be recovered even in aged cells that had lost their original cell properties.ConclusionsA DCP culture method using a biomimetic hydrogel blanket provides cells with an adjustable physical pressure and a low-oxygen environment. Through this technique, we could maintain the original cellular phenotypes and intrinsic properties of human primary chondrocytes. The results of this study can be applied to other cells that require special pressure and oxygen concentration control to maintain their intrinsic properties. Additionally, this technique has the potential to be applied to the re-differentiation of cells that have lost their original properties.

BackgroundThe restoration of the functional ability of mesenchymal stem cells (MSCs) using epigenetic modification is very promising for patients with weak osteogenesis ability. This study focused on the acceleration of osteogenesis from MSCs using microRNA (miRNA)2861 and a cell-penetrating peptide (CPP), LK.MethodsWe performed MSCs penetration test of complex between the LK peptides and miRNA 2861. Three different experiments were performed to investigate the effects of miRNA 2861 on osteogenic differentiation in MSCs: 1) intensity of alizarin red staining, which reflects the status of mineralization by osteoblasts; 2) gene expression related to osteoblast differentiation; and 3) confirmation of corresponding protein translation for comparison with RNA expression levels.ResultsWe found that cLK effectively delivered miRNA 2861 into the cytoplasm of human MSCs and accelerated osteogenic differentiation from MSCs, as well as mineralization.ConclusionThe complex of miRNA 2861 with LK may have a positive effect on the osteogenic differentiation from MSCs and mineralization. Therapies using miRNAs combined with LK may be good candidates for the augmentation of osteogenesis in patients.